Henry John Temple, 3rd Viscount Palmerston

Henry John Temple, 3rd Viscount Palmerston (20 October 1784-18 October 1865), better known as Lord Palmerston, was Prime Minister of the United Kingdom from 6 February 1855 to 19 February 1858 (succeeding George Hamilton-Gordon and preceding Edward Smith-Stanley) and from 12 June 1859 to 18 October 1865 (succeeding Smith-Stanley and preceding Lord John Russell). Palmerston started his career as a Tory before joining the Whigs and becoming Prime Minister as leader of the newly-founded Liberal Party.

Early career
Henry John Temple was born in Westminster, Middlesex, England on 20 October 1784 to a family of Anglo-Irish peers, and he succeeded his father as Viscount Palmeston in 1802 at the age of 18. He volunteered for the British Army in 1803 when it was rumored that Emperor Napoleon I was preparing a French invasion of the British Isles, and, in November 1806, he was elected the Tory MP for Horsham; he was unseated in January 1807 when the Whigs backed a petition to remove him from Parliament. In June 1807, he returned to the House of Commons as MP for Newport, a pocket borough on the Isle of Wight. From 1809 to 1828, he served as Secretary at War, and he organized the finances of the British Army during the Napoleonic Wars. In 1822, he defected to the Whigs, and he served as Foreign Secretary from 1830 to 1834, from 1835 to 1841, and from 1846 to 1851, becoming one of the forefathers of the diplomatic policy of liberal interventionism through his belligerent actions during European conflicts. Palmerston supported the Revolutions of 1848 due to his support for national self-determination, but he staunchly opposed Irish independence and the Young Ireland movement. In 1851, he was forced to resign after the royal family objected to his unauthorized public support for Louis-Napoleon Bonaparte's seizure of power in France. He went on to serve as Home Secretary from 1852 to 1855, enacting various social reforms while opposing electoral reform.

Premierships
In 1855, public dissatisfaction with the Crimean War led to the downfall of Aberdeen's coalition government, and Palmerston became the new Prime Minister. He sustained a majority despite growing popular unrest, and he appealed to the public through nationalism, becoming a popular leader affectionately nicknamed "Pam". However, he was trusted by neither Queen Victoria nor the political establishment of the time. Apart from the victory in the Crimean War, Palmerston also led the United Kingdom to victory over Qing China in the Second Opium War of 1856-1860, humiliating the Manchus for a second time. In 1857, he passed an act allowing for courts to grant a divorce and removing divorce from the jurisdiction of the international courts, leading to parliamentary outrage. He oversaw the passage of the Government of India Act 1858 following the Sepoy Rebellion, ending the British East India Company's autonomous rule over India and creating the state of British Raj. His first downfall came when, in the aftermath of the Italian republican Felice Orsini's assassination attempt on Napoleon III with a British-made bomb, Palmerston's attempts to pass a bill outlawing the planning of overseas murders from British soil were defeated by the Conservative Party. Palmerston was forced to resign as a result of his failure to pass the bill.

In 1859, Palmerston returned to power as the leader of the new Liberal Party, becoming Britain's first Liberal prime minister. After Lord John Russell and William Ewart Gladstone agreed to serve under Palmerston if he was appointed to form a government by the Queen, Queen Victoria mandated Palmerston to form a Liberal government. Palmerston was sympathetic towards the Confederacy during the American Civil War; despite his opposition to slavery and the slave trade, he sought to weaken the United States by supporting its disunity, and he also sought to have an overseas market for British goods. On 13 May 1861, Britain proclaimed its neutrality in the war, but the Trent Affair of November 1861 nearly led to war between Britain and the Union. Britain was complicit in the fitting of Confederate raiders in British ports, including the CSS Alabama, built in Birkenhead. In 1862, the overthrow of the Greek king and Russian activity in Central Asia distracted Britain from the Civil War, and Britain ultimately remained neutral. In July 1865, the Liberals increased their parliamentary majority following an election victory, but he died just months later at the age of 80.